This is unusual. I can't replicate it from the bug save state or in games I've tried with myself. It may be something wrong with the BoardGameArena website itself. It is possible that it could be fixed by a refresh without cache of the main page (and possibly game page).

To reload a page in Google Chrome without using the cache, you can perform a hard refresh:
On Windows or Linux - Press and hold Ctrl and click the Reload button, or press F5 while holding down Ctrl
On Mac - Press and hold ⇧ Shift and click the Reload button, or press R while holding down ⌘ Command and ⇧ Shift

It may also be bad data in the database that goes away after a few turns. Let me know if it still keeps happening and I can report it to the BoardGameArena main site developers. Sorry for the inconvenience in the mean time.

Also, if you click on your avatar on the top right of the main page. Does the percent progression shown in the pop out drawer for that game match the percent progression shown in game (on the top left)?

I managed to replicate this issue on my fourth attempt. I asked on the dev Discord channel. Apparently, this is a known bug in BoardGameArena's main site. They are looking into it. There is a process that runs every hour that should clear these issues. It sounds like they are struggling to identify what is causing this issue.

I'm sorry again for the inconvenience. Thanks for reporting it. Please let me know if it happens again.